Conventionally, a trip computer or a drive monitor as an in-vehicle display apparatus displays vehicle information including at least one of fuel consumption, a driving distance of residual fuel, an average speed, external temperature and the like in addition to a total travel distance (i.e., an integral travel distance or an odometer) and a sectional travel distance (i.e., a reset type distance meter or a trip odometer). The vehicle information includes preliminary determined items, so that the apparatus displays to switch from one item to another item. The in-vehicle display apparatus is defined as an in-vehicle meter apparatus, and disclosed in, for example, JP-A-2011-100019, JP-A-2009-168557, JP-A-2003-252080 and JP-A-2011-46327. The apparatus, in general, includes a display device and one operation device such as a push button. The display device switches to display each item such as the driving distance and the fuel consumption in a predetermined order every time an user operates the operation device.
Here, FIG. 7 shows a flowchart of a switching display mode of items in a conventional in-vehicle display apparatus. In FIG. 7, a dotted arrow represents an operation of the user who pushes, the operation device for a short time. A solid arrow represents an operation of the user who pushes the operation device for a long time. FIG. 8 shows a display device 900 in the conventional in-vehicle display apparatus. The display device 900 includes: a switching display element 910 for switching and displaying at least one item among multiple items having various contents such as the driving distance and the fuel consumption; and a time display element 920 for displaying time. As shown in FIG. 7, when the user pushes the operation device for a short time, the content to be displayed on the switching display element 910 is switched in the predetermined order such as an order from the total driving distance, the sectional driving distance, the driving distance of residual fuel, the average fuel consumption, the instantaneous fuel consumption, the average speed, to the external temperature. When the switching display element 910 displays the total driving distance, and the user pushes the operation device for a long time, the display device 920 switches to a time adjustment mode, in which the present time of the time display element 920 is adjusted. When the switching display element 910 displays the sectional driving distance, the average fuel consumption or the average speed, and the user pushes the operation device for a long time, the displayed sectional driving distance, the average fuel consumption or the average speed is reset to be zero.
Thus, in the conventional art, the switching operation of the content of the item to be displayed on the switching display element, the time adjustment operation and the reset operation are executed according to one operation of the operation device such as a short time pushing operation and a long time pushing operation. In view of recent requirements of the user, the number of items to be switched and displayed on the switching display element increases according to usage setup. Accordingly, in a conventional art such that the switching display operation is executed by one operation of the operation device, it is necessary to push the operation device multiple times until a required item is displayed on the display element. Thus, a requirement of the HMI (human machine interface) for the user who operates the operation device while the user drives the vehicle is not satisfied.
Further, as shown in FIG. 9, it is required for the apparatus to have multiple switching display elements so that multiple contents of items are displayed at the same time. In FIG. 9, the apparatus includes two switching display elements 930, 940. Here, a dotted arrow represents an operation of the user who pushes the operation device for a short time. In FIG. 9, a first switching display element 930 switches and displays one of the external temperature, the driving distance of residual fuel, the average fuel consumption, the instantaneous fuel consumption, and the average speed in this order. A second switching display element 940 switches and displays the total driving distance and the sectional driving distance alternately. Here, when the switching display operation in FIG. 9 is performed by one operation of the operation device, a combination of items to be displayed on the first and second switching display elements 930, 940 at the same time may be limited. Specifically, in FIG. 9, for example, when the second switching display element 940 displays the total driving distance, the first switching display element 930 always displays the external temperature. When the second switching display element 940 displays the sectional driving distance, the first switching display element 930 displays a content other than the external temperature. Specifically, in FIG. 9, both of the external temperature and the sectional driving distance are not displayed at the same time. Thus, the user needs are not satisfied sufficiently.
Thus, the apparatus may include multiple switching display elements, and each switching display element includes a respective operation device. In this case, the number of contents to be displayed and switched on each switching display element is reduced, compared with a case where the apparatus includes only one switching display element. Thus, the number of operation times for displaying the required item of the user is reduced, and a combination of items to be displayed on each switching display element is not limited excessively. However, in this case, it is necessary for the user to determine which operation device the user should operate when the user wants to display one of items as the required item. When the user drives the vehicle, it is difficult for the user to select one of the operation devices immediately. Further, it may be necessary for the user to see the apparatus for a comparatively long time. Furthermore, since the apparatus includes multiple operation devices, the number of elements for providing the apparatus increases, so that a manufacturing cost of the apparatus is made high.